Bioterrorism-related inhalational anthrax in an elderly woman, Connecticut, 2001

Abstract

On November 20, 2001, inhalational anthrax was confirmed in an elderly woman from rural Connecticut. To determine her exposure source, we conducted an extensive epidemiologic, environmental, and laboratory investigation. Molecular subtyping showed that her isolate was indistinguishable from isolates associated with intentionally contaminated letters. No samples from her home or community yielded Bacillus anthracis, and she received no first-class letters from facilities known to have processed intentionally contaminated letters. Environmental sampling in the regional Connecticut postal facility yielded B. anthracis spores from 4 (31%) of 13 sorting machines. One extensively contaminated machine primarily processes bulk mail. A second machine that does final sorting of bulk mail for her zip code yielded B. anthracis on the column of bins for her carrier route. The evidence suggests she was exposed through a cross-contaminated bulk mail letter. Such cross-contamination of letters and postal facilities has implications for managing the response to future B. anthracis-contaminated mailings.

Figure 1

Bioterrorism-related inhalational anthrax cases by week of symptom onset—United States, 2001.The first two cases of inhalational anthrax occurred in Florida. Though no direct exposure source was found, environmental samples of the media company in which these two patients worked and the postal facilities serving the media company yielded Bacillus anthracis spores specifically implicating a B. anthracis–containing letter or package (4): †, the letters to Senators Thomas Daschle and Patraick Leahy were postmarked in the Trenton, New Jersey, processing and distribution center on October 9, 2001; black bars indicate cases of inhalational anthrax in persons with direct exposure to a B. anthracis–containing letter; gray bars indicate cases of inhalational anthrax persons with no known B. anthracis exposure.

Figure 2

Diagram of a letter-sorting machine